Electrical switch



Nov. 4, 1958 a w'CoNcELMA-N 2,859,311 ELECTRICAL SWITCH I 2 Sheets-Sheet1 Original Filed Nov. 16. 1953 Nov. 4, 1958 c. w. CONCELMAN ELECTRICALSWITCH Original Filed Nov. 16. 1953 2 Sheets-Sheet 2 United StatesPatent ELECTRICAL SWITCH Carl Concelman, Danbury, Conn., assignor, bymesne ass gnments, to Amphenol Electronics Corporation, Chicago, 111., acorporation of Illinois Continuation of application Serial No. 392,237,November 16, 1953. This application October 31, 1955, Serial No. 543,785

4 Claims. (Cl. 200-153) General This invention relates to electricalswitches of the type which selectively connects a first high-frequencywavesignal coaxial transmission line to any of a plurality of suchlines.

This application is a continuation-in-whole of applicants applicationSerial No. 392,237, filed November 16, 1953, entitled Electrical Switch.

One prior type of electrical switch for selectively interconnectingcoaxial transmission lines utilizes a single relayactuated spring bladepivotally mounted at one end thereof which is fixedly and conductivelyattached to the inner conductor of a first transmission line. The otherend of .the switch arm is displaceable between closely spaced innerconductors of a pair of transmission lines for selectively connectingthe individual inner conductors thereof to the inner conductor of thefirst transmission line. While a switch of this type has desirablecharacteristics, it has the limitation in certain applications that anunterminated inner conductor extends into the high-frequency energyfield and, thus, picks up so-called cross-talk signal energy. Moreover,the voltage standing-wave ratio developed by this type of switch maybeundesirably high for some applications. Various rotary switches havealso been proposed, but in general these may be more expensive tomanufacture than is desirable for some applications.

lt is an object of the present invention, therefore, to provide a newand improved electrical switch of the type described which avoids one ormore of the above-mentioned limitations of prior switches of this type.

It is another object of the invention to provide a new and improvedelectrical switch of simple and inexpensive construction for selectivelyconnecting -a first high-fiequency wave-signal coaxial transmission lineto any of a plurality of such lines.

, It is another object of the invention to provide a new and improvedelectrical switch of the type described adapted for use in thehigh-frequency range and which may be readily constructed largely byscrew-machine operations. -It is another object of the invention toprovide a-new and improvedelectrical switch of the type described whichis of simple construction adapted for use in the high frequency rangeand which resultsin reduced cross talk. ,In'accordance with a particularform of the invention, an electrical switch for selectively connecting afirst highfrequency wave-signal coaxial transmission line to any of aplurality of such lines. comprises a support having a chamber defined byconductive walls. The switch includes a first coaxial connector forconnection to the first transmission line and having an outer conductorconductively connected to the chamber walls and having an inner con-'ductor extending into the chamber. The switch also includes a pluralityof coaxial connectors for individual connection; to the plurality oftransmission lines having outer conductors conductively connected to thechamber walls and having inner conductors. The switch also includesapluralityof movable conductive switch arms;

Patented Nov. 4, 1958 individually conductively connected to the innerconductors of the plurality of connectors and extending within thechamber radially to the inner conductor of the first connector and theaxes of the plurality of switch arms being substantially along a commonsurface substantially perpendicular to the inner conductor of the first'connector for selectively conductively connecting the individual innerconductors of the plurality of connectors to the inner conductor of thefirst connector or to the chamber walls. The switch also includesactuating means for selectively operating the switch arms.

For a better understanding of the present invention, together with otherand further objectsthereof, reference is had to the followingdescription taken in connection with the accompanying drawings, and itsscope will be pointed out in the appended claims. Referring to thedrawings: Fig. 1 is an elevational view, partly in section, of anelectrical switch constructed in accordance with a particular form ofthe invention;

Fig. 2 is an end elevational view of the switch as along the line 22 ofFig. 1; Fig. 3 is an elevational view of a modified electrical switchconstructed in accordance with the invention;

Fig. 4 is a sectional view of the Fig. 3 switch as seen along the line44 of Fig. 3, and y I Fig. 5 is a sectional view of the Fig. 3 switch asseenalong the line 5-5 of Fig. 4.

Description of Fig. 1 electrical switch Referring now more particularlyto Fig. 1, 'there, is, represented an elevational view, partly insection, of an electrical switch 10 constructed in accordance with theinvention for selectively, connecting a first high-frequency wave-signalcoaxial transmission line to any of a plurality of such lines. Theswitch 10 includes a support llhaving a chamber 12 which may, forexample, be of substanitally; uniform, square cross section andpreferably is substan: tially less than one-half wave length long overthe oper; ating frequency range of the switch 10. The chamber 12' isdefined by conductive Walls including wall 13, as shown in the drawings.The support 11 may be constructedof any suitable material such as brasswhich may then be silver plated. a

A plurality of coaxial connectors are electrically coupled to chamber12. These connectors provide individual connection to transmission linesand having outer conductors conductively connected to the chamber wallsand inner conductors which preferably extend into the chamber. Moreparticularly, a pair of like cylindrical connectors 14 and 15 ofpredetermined diameter are, for example, disposed along a predeterminedlongitudinal axis of the chamber and have outer conductors 16' and 17,respectively, conductively connected to and elfecti vely" tangential tothe chamber walls at opposite ends of the chamber 12. By effectivelytangential" is meant that: the outer cross-sectional dimensions of thechamber 12' preferably are approximately equal to the inner diameter: ofthe outer conductors of the connectors 14 and 15L Inner conductors 18and 19 of the connectors 14 and 15 preferably are spaced from therespective outer con}:

- ductors thereof by suitable bodies of dielectric material W axisextending into the support 11 along the 'a'xislof t 18a and 19aextending into the chamber 12 and fixedly" disposed Within the outerconductors 16 and 17. The connectors 14 and 15 may be of any suitabletype and may, for example, comprise connectors of the type described andclaimed in Patent 2,540,0l2-Salati, entitled Elecconnector 15. Referringagain to Fig. 1, the connector 20 preferably is disposed approximatelymidway between the pair of connectors 14 and and has an inner conductor21' which preferably extends into the'cha'm'ber Hand is supported withinthe connector by a body of suitable dielectric material 22 fixedlydisposed in a stepped bore 13zz in the support 11.

A pair of movable conductive switch arms 23 and 24, preferably ofresilient material, such as beryllium copper, are individuallyconductively connected and secured to the inner conductors 18 and 19 ofthe connectors 14 and 15, respectively, by any suitable means such assoldering. The arms 23 and 24 preferably are seated in suitable slots inthe inner conductors 18, 19 and dielectric spacers 18a, 19a,respectively, to provide a rigid mechanical support for the arms. Thearms 23 and 24 preferably extend within the chamber to the innerconductor 21 of the connector on opposite sides thereof for selectivelyconductively connecting the individual inner conductors 18 and 19 of theconnectors 14 and 15 to the inner conductor 21 of the connector 20 or tothe chamber wall 13. Suitable contact points 25 and 26 are attached tothe ends of the switch arms 23 and 24, respectively, for effecting thedesired contact between the respective switch arms and the innerconductor 21 or the chamber wall.

As will be more fully explained hereinafter, the arms 23 and 24 areshown under stress with the arm 24 conductively connected to the innerconductor 21 of the connector 20 and the other arm 23 preferablyconductively connected to an adjustable conductive contact screw 27 inthe support 11 for effecting a conductive connection to the chamber wall13. The arm 24 preferably is conductively connected 'in the absence ofstress thereon to anadjustable conductive contact screw 28 in thesupport 11 and the other arm 23 preferably is conductively connected inthe absence of stress thereon to the inner conductor 21 of the connector20.

The switch 10 also includes actuating means for selectively effectingconductive connection of one ofthe arms 23, 24 to the inner conductor 21of the connector 20 or to the chamber wall 13 and the other arm to thechamber wall 13 or to the inner conductor 21 of the connector20,respectively. The actuating means comprises, for example, a pair ofcylindrical dielectric members 29 and 30 extending through apertures inthe wall 13 into the chamber 12 and slidably disposed normal to the arms23 and 24, respectively, for deforming the arms in one position thereof,shown in the drawings, selectively to effect conductive connection ofthe arm 24 under stress to the inner conductor 21 of the connector 20and the other arm 23 under stress to the chamber wall 13.

i There preferably is also provided control means comprising anelongated cam-operated spring-mounted member 31 for simultaneouslydisplacing the dielectric members 29 and 30 to effect the switchingoperation. As represented in Fig. 2, the member 31 is attached by meansof a spring 32 to a mounting bracket 33 for the switch 10. A slidablydisplaceable cam 34, as indicated by the arrows, is mounted on thebracket 33 and operatively connected to a push-pull switch button 35, asindicated by a broken line 36.

From the foregoing description, it will be seen that the variousapertures in the support 11 may be formed quickly and conveniently byinexpensive screw-machining operations. The outer conductors of theconnectors 14, 15, and 20 may be made in a similar manner and the innerconductors thereof may then be assembled and held in a spaced coaxialrelation with the respective outer conductors b'y insulators. The switcharms 23 and 24 may be "fabricated by simple stamping operations. Afterthe switch is assembled, a suitable cover 37, represented in Fig. 2,"maybe utilized to complete the switch housing. Thus, the manufactureof theswitch 10 lends itself to mass production techniques and the costthereof is relatively low.

Referring to Fig. 2, when the switch button 35 is in the position shownin the drawings, the cam 34 supports the member 31 in the position shownwhich, in turn, maintains the dielectric actuating members 29 and 30 inthe position represented in Fig. .1. In this operating condition, theinner conductor 19 of the connector 15, which may, for example, serve asan output connector, is connected by the switch arm 24 to the innerconductor 21 of the connector 20 which may, for example, supplyinput-signal energy to the switch. The inner conductor 18 of the otherconnector 14, which may, for example, also be an output connector, isconnected to the chamber wall 13 through the screw 27 which may beadjusted for desired contact pressure. The switch arms 23 and 24 effectthe respective connections just described under stress exerted thereonby the dielectric members 29 and 30, respectively.

When the switch button 35 of Fig. 2 is pushed "toward the mountingbracket 33, cam 34 moves into a position which allows the member 31 tospring away from the support 11 as a result of the resiliency of thespring 32. The resilient switch arms 23 and 24 then spring into contactwith the inner conductor 21 and the screw 28, respectively, and displacethe dielectric members 29 and 30 accordingly.

Since there is provided a conductive connection between the chamber wall13 and the inner conductor of the connector 14 or 15 which isdisconnected from the inner conductor 21 of the connector 20, the energypickup resulting from capacitive coupling of the dis connected connectoris substantially reduced. This res'ults'in reduced cross talk betweenthe input connector 20 and the output connector 14 or 15 disconnectedthere: from.

It is well known that the characteristic impedance of a high-frequencywave-signal coaxial transmission line is a function of the ratio of theinner diameter of the outer conductor of the transmission line and theouter diameter of the inner conductor thereof. Similar considerationsapply to the characteristic impedance of the transmission lineeffectively formed by the conductive walls of the chamber 12 and theswitch arm 23 or 24.

Accordingly, the cross-sectional dimensions of the chamber maybeapproximately equal to the diameter of the outer conductors of theconnectors 14, 15, and 20.- The dimensions of the switch arms 23 and24may'then be selected approximately to provide a desiredcharacteristicimpedance for the transmission line eifectively formed bythe chamber walls and the switch arm 23 or-24.

By proportiom'ng the length of each half of the chamber 12 to besubstantially less than one-quarter wave length over the operating rangeof the switch 10, impedance discontinuities within the effectivetransmission line formed by the chamber 12 and switch arms 23, 24

can be conveniently proportioned approximately toca n c'el each otherover the operating range. For example, the increase of capacityintroduced into the transmission line by the extension of the dielectricspacer 18a into the chamber 12 may be approximately canceled by thereduction'of capacity present in the region surrounding the innerconductor 21 due to recesses in the chamber walls provided by bore 13a.Above the normal operating range of the switch 10, as the electricalspacing between the above-mentioned discontinuities approvided betweenthe transmission line connected to the connector 20 and the transmissionline connected to either of the connectors 14 and 15. In this manner, arelatively low voltage standing-wave ratio may result for the switch 10.

While applicant does not wish to be limited to any particulardimensions, the following approximate dimensions have been employed in aswitch constructed in accordance with the invention for use at signalfrequencies in the range of 100-to 1000 megacycles:

Length of support 11 inches 2 Width and height of chamber 12 do A Lengthof switch arms 23, 24 do Width of switch arms 23, 24 do .200 Thicknessof switch arms 23, 24 ...do .008 Spacing between conductor 21 anddielectric membBI'S 29, 30 inches /8 Extension of conductor 21 intochamber 12 w inches-.. 11/64 Diameter of conductor 21 do .084 Nominalcharacteristic impedance of efiective transmission line of chamber- 12and switch arms 23, 2 ohms 50 Description ofFig. 3 electrical switchReferring now to Fig. 3, there is represented an elevation'al view of amodified electrical switch 50 constructed in accordance with theinvention and generally similar to the switch-represented in Figs. 1 and2. As represented in Fig. 4, which is a sectional view of the switch 50taken along the line 4-4 of Fig. 3, the switch 50 includes a' support51. preferably having a pair of elongated, substantially parallel andlongitudinally aligned chambers 52, 53 defined by the conductive wallsof the support 51 and a suitable conductive member 54 which separatesthe chambers within the switch 50.

Twopairs of coaxial connectors 56, 57 and 58,59

which may, for example, be output connectors, preferably have outerconductors conductively connected to the walls of the individualchambers adjacent the ends thereof A coaxial connector 60 serving, forexample, as an input connector preferably has an outer conductor 61conductively connected to the walls of one of the chambers approximatelyat the mid-point thereof and has an inner conductor 62 extending intoboth of the chambers52and 53 through a. suitable bore 63 in the member54. t V f Two pairs of movable conductive switch arms, preferablycomprising resilient leaf springs 64, 65 and 66, 67, are conductivelyconnected to the inner conductors of the corresponding connectors 56, 57and 58, 59, respectiyely, and preferably are conductively connected inthe absence-of stress thereon chamber walls, as, representedin Fig; 5,which is a sectional view of the switch 50 taken along the line 5-5 ofFig. 4.

Two pairs of elongated dielectric actuating members 68, 69 and 70, 71preferably extend through the chamber walls into the individual chambersand may, for example, be individually slidably disposed approximatelynormal to the arms 64, 65 and 66, 67, respectively, for deforming thearms selectively to eifect conductive connection of one of the armsunder stress to the inner conductor 62 of the connector 60 and the otherarms to the chamber walls. There preferably is also provided controlmeans for successively displacing the dielectric members to effect theswitching operation. This control means comprises, for example, arms 72and 73, represented in Fig. 4, responsive to energization of solenoidrelays 74 and 75, respectively, for displacing the dielectric actuatingmembers 68 and 71, respectively. Similar solenoid relays, such as therelay 76 of Fig. 3 and another relay (not shown), may be provided tocontrol the displacement of the dielectric members 69 and 70.

Operation of.Fig. 3'electrical switch The operation of the, switch 50,represented in Figs. 3, 4, and 5, may be best understood by referring toFigs; 4 and 5. When the solenoid relays individually controlling theswitching operation are de-energized, the corresponding switch elements,such as 64 and 65, are conductively connected to the chamber walls intheir nor-' mal positions, as represented in Fig. 5. When one of therelays, such as the relay 74 of Fig.4, is energized, the relay arm 72exerts a force which displaces the dielectric member 68, causing theswitch arm 64 to con tact the inner conductor 62 of the connector 60. Inthis operating condition, the output connector 56 is actively connectedto the input connector60 while the remaining connectors have innerconductors which are conductively connected to the chamber walls and,thus, are effectively disconnected from the input connector. z

By means of a'suitable electrical switch, not shown, which controls theenergization of the solenoid relays, any selected output connector maybe connected to the input connector 60 while the remaining connectorsare eifectively disconnected therefrom. It will also be understood thatany suitable number of chambers andoutput connectors may be aligned,with the chambers 52 and 53 to form, for example, ,a fiveor six-positionswitch. These'chambers. may individually be proportioned ina mannersimilar to the'chamber 12 of the Fig. 1 switch.

From the foregoing description, it will be apparent that a switchconstructed in accordance with the inven-' tion has the advantage ofbeing simple in construction and inexpensive to manufacture. The switchhas the additional advantage of providing reduced undesired cross talkbetween input and output connectors thereof. The switch also providessatisfactory.standing-wave ratios in, for example, the to 1000 megacyclerange.

While there have been described what are at present considered to be thepreferred embodiments .of this invention, it will obvious to thoseskilled in the art that various changes and modifications may be madetherein without departing from the invention, and-it is, therefore,aimed to cover all such changes and modifications as fall within thetrue spirit and scope of the invention.

What is claimed is:

1. An electrical switchfor conductively connecting a firsthigh-frequency wavesignal coaxial transmission line to any one of aplurality of such lines comprising, 'a switch support having an internaland substantially hollow chamber extending longitudinally betweeninterior conductive end walls, said chamber having a substantiallyuniform cross-section defined by confronting pairs of parallel andinterior conductive walls, a first coaxial con nector electricallycoupled to said chamber intermediate the end walls thereof and adaptedfor connection with the first of said transmission lines, said connectorhaving an outer conductor conductively connected to said chamber wallsand an inner conductor extending into said chamber and terminatingtherein wherein the axis of said connector in the region where iteifects electrical coupling to said chamber is substantiallyperpendicular to the longitudinal dimension of said chamber, a coaxialconnector electrically coupled to said chamber on each side of saidfirst connector 'and defining a plurality of connectors for individualconnection to respective ones of said plurality of transmission lines,said plurality of connectors each having an outer conductor conductivelyconnected to said chamber walls and an inner conductor terminating insaid chamber, a plurality of movable conductive switch arms having asubstantially uniform crosssection defined by opposed pairs of parallelsurfaces, said arms extending substantially longitudinal-wise in saidchamber for movement from one to another of two positions wherein saidfirst connector is alternately connected to and disconnected fromrespective ones of said plurality of connectors, each arm having oneendconductively connected to and supported -from a'respective one of theinner conductors of said plurality and having a free end adapted forconductive connection with the inner con ductor of said-first Connector,wherein each arm and the coextending chamber walls surrounding sameserve as a section of coaxial line coupling said first connector with arespective one of the plurality of connectors when the correlated arm ispositioned to effect conductive connection with the inner conductor ofsaid first connector. An electrical switch for conductively connecting afirst high-frequency wave-signal coaxial transmission line to'any one ofa plurality of such lines comprising, 'a switch support having aninternal and substantially hollow chamber extending longitudinallybetween interior conductive-end walls, said chamber having asubstantially uniform cross-section defined by confronting pairs ofparallel and interior conductive walls, a first coaxial connectorelectrically coupled to said chamber intermediate the end wallsthereofand adapted for connection with the first of said transmissionlines, said connector having an outer conductor conductively connectedto said chamber walls and an inner conductor extending into said chamberand terminating therein wherein the axis of said connector in the regionwhere it effects electrical coupling to said chamber is substantiallyperpendicular to the longitudinal dimension of said chamber, a' coaxialconnector electrically coupled to said chamber on each side of saidfirst connector and defining a plurality of connectors forindividualconnection to respective ones of said plurality of transmission lines,said plurality of connectors each having an outer conductor conductivelyconnected to said chamber Wallsand an inner conductor terminating insaid chamber, a plurality of movable conductive switch arms having asubstantially uniform cross-section definedby opposed pairs of parallelsurfaces, said arms extending substantially longitudinalwise in saidchamber for movement from one to another of, two positions wherein saidfirst connector is alternately connected to and disconnected fromrespective ones of said plurality of connectors, each arm having one endconductively connected to and supported from 2. respective one of theinner conductors of said plurality and having a free end adapted forconductive connection with the inner conductor of saidfirst connector,movement of an arm to a first of its positions causes the free endthereof to contact conductively with a chamber wall juxtaposed the firstinner conductor, movement of an arm to the second of itspositions causesthe freeend thereof to contact conductively with'the innerconductorofsaid first connector wherein such arm and the coextending chamberwallssurrounding same serve as-a section of coaxial line coupling said firstconnector with the correlated connector of said plurality.

3. Apparatus ase defined in claim 2, wherein-the crossnected to saidchamber walls, said connector also having an inner conductor extendingthrough a first of said chambers and "extending into and terminatingWithin a second "ofsaid chambers, the axial dimension oi said innerconductor being substantially perpendicular to the longitudinaldimension of said first and second chambers and beingdisposedintermediate thejend Walls thereof, pairs of coaxial connectorsfor individual connection to said plurality of transmission lines" andhaving outer conductors conductivelyl'connected"to' said chamber walls,the inner conductorsof each pair of connectors extending into respectiveones of said chambers on. opposite sides of the inner conductor o'f "thefirst connector, pairs of movable conductive fswitch arms having asubstantially uniform cross-section defined by 0pposed pairs of parallelsurfaces, one 'pair of each or said arms extending substantially"longitudinal wise "inia respective chamber for movement'from'one'toanother or two positions wherein said first connector is alternatelyconnected to and disconnected from respective onesof said plurality ofconnectors,-each arm having oneje n d conductively connected to andsupported 'from a respective one of theinner conducotrsiof saidpluralityand having a free end adapted for conductive connectionwith'the inner conductor of saidfirst connectorfjand means foroperatingsaid switch arms wherein movement ofa'narm to 'a first of itspositions causes he free end of said arr'nto contactcondu'ctively'with'the chamber wall juxtaposed'the first innerconductor,'an'd movement of an arm to the second of its positionscauses'itsfree'end to make contactlwith said first inner conductorwherein such arm and the coextending chamberfwall'surrounding same serveas a section'of coaxial line couplingsaidjfirst connector with thecorrelated connector of said'plurality.

References Cited in the file of this patent H UNITED STATES PATENTSDorne Dec.-9,"l94 7 Ellis et al. July.17,'*l951

